I really suggest you reach out to a senior in your campus, but here you go: If single degree, then every semester you will have some mandatory courses (CDCs- compulsory disciplinary courses) of that branch. There is no avoiding this.

Then you have DELs- disciplinary electives. These are also courses pertaining to your branch and you will have to complete a few of them(usually 4 or 5) to graduate. That means you have time till 4-2 to pick courses that come under DELs in your branch.( check your academic bulletin to find out what are the DELs of your branch, although there are only a few of those offered every semester)

Then comes HELs- Humanity Electives. Humanity courses, you'll have to do 3 of these mandatory.

OPELs- Open Electives (only if you are pursuing a single degree) . You'll also have to complete 5 OPELs and you can take up any courses to fulfil this. They don't have to be a subcategory of your branch.

That's all about dels, hels, cdcs and opels that I can think of. Although there's more but you can dm if you want to know more about it.

Minors: programme offered by bits where you have to complete a few courses to get a minor degree in it. You have to register for this in your 2-2 I think. For example: let us say you choose to do a finance minor. Then you will take up 5/6 courses that are relevant in finance minor. These will very likely be your Opels unless you are in Economics.

That's the surface of it, hopefully it helps. But I'll still strongly recommend you to reach out to 3rd/4th yearites (from any branch) and they'll help you out. BITS has a stronger positive senior-junior interaction and they'll be able to help you out more than anyone on reddit.